Downloaded from https://www.everyspec.com MIL-STD-81OD 19 iJuly.1983 An item should be tested to a category when the item is either O a. intended for use within that category as a mission requirement or b. expected to spend a significant portion of its service life within that oategory aa a consequence of its deployment, storage, or use. ~ An item will probably be tested to more t~ category. For example, ~. equipment installed in jet airoraft is covered by categories 1 (Basic Trans- portation) and 5 (Jet,Aircraft/Tactical Missiles) and may ‘be teated in both environments. . 1-3.1.1 of envirqnmenta tiP tO teat ,.
1-3.1.1.1 If an item is expected to -- encounter more than one vibration environment as a consequence of ita intended use, the environments should be compared. If any of them would apply similar stress levels or similar bandwidth, the moat severe category test should be ,: applied as representative. .,, ,. 1-3.1.1.2 t. n If the transportation vibration levels are more severe than the application-induced vibration levels, as is often true for ground-based and some shipboard equipment, both transpor- tation and platform vibration teats should be performed.
This is because the transportation teat is performed with the equipment nonoperating and th,eplat- form test ia performed with the equipment on. ~If the application.vibration levels are more severe “thanthe transportation levels,.further snalyais must be performed to compare the fatigue potential of both environments over the life cycle. If the platform environment is still found to be more severe, the transportation teet can be deleted. I-3.2 e of related test c~. . . Guidance for.eetting teat valyes is given below with the discussion of each vibration environment category. The provisions of section I-U of this method apply for each test designed‘under this method. ..!.
For categories I thru III, the following defifiitionsapply: a. ~. Cargo which ia securely tied or blo”ckedin all three axes with respect to the bed of the tranaport vehicle. ~. Cargo which is blocked or tied in the two horizontal axea with respect to the bed of the transport vehicle. .- ia not tied, blocked,’.or reatraineilwhen vehicle. C. LWWXU3Q. cargo whi?~ placed on the bed of the tranaport A test for restrained cargo is not teat may be devisedby .uaingfield procedure. included in the measurements to categories below. Such .a tailor the most appropriate; METHOD 514.3 19 July 1983 5 i14.3-4